4-Carboxybenzaldehyde was condensed with cyanoacetic acid to afford 1-carboxy-4-(2-cyano-2- carboxyvinyl)benzene (1). Homopolyamides were prepared from the polycondensation of I with aromatic diamines utilizing triphenyl phosphite and pyridine as condensing agents. In addition, various copolyamides were prepared by reacting a mixture consisting of 1 and terephthalic acid with an aromatic diamine. The synthesized polyamides contained olefinic bonds and pendent cyano groups. The homopolyamides showed higher solubility in common solvents than did the reference polyamide prepared from terephthalic acid and an aromatic diamine. Their differential thermal analysis traces revealed that they softened between 200°C and 300°C. Upon curing at 300°C for 70 h, they yielded heat-resistant crosslinked polymers. The thermal stabilities of the cured polymers were correlated with the curing conditions and their composition. They displayed higher thermal stability than the reference polyamide and were stable up to 372-405°C in N2. Furthermore, they are noteworthy for their high char yield at 800°C, namely, 68-78% in N2 and 58-69% in air.
Посилання на статтю:
Cyano-substituted polyamides derived from 1 -ca rbo xy-4- (2-cya n o- 2- carboxyvinyl)benzene and their heat-curing to thermally stable resins / John A. Mikroyannidis // Polymer. – 1994. – Vol 35. – P. 630-635.